p4.mailcloud.com.tw has no NS records.
NS records for this zone are defined at mailcloud.com.tw.
NS records for this zone are defined at mailcloud.com.tw.
Question and response
Question
dig p4.mailcloud.com.tw. NS
Answer
The response has no answer records.
Authority
mailcloud.com.tw. 900 SOA ns-848.awsdns-42.net. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0